last time I looked Brotli format do not clearly define its frame format, such as there is a good chance that a random stream of data would be decoded as valid brotli compressed data.
Common reason being someone forgot to check how many bytes read() actually returned and just assume it filled the buffer.
Robust data formats have double protection against this class of bugs with unambiguous SOF and EOF boundaries that the consumer can assert. I guess a sanity-byte once every X Megabytes wouldn’t hurt either.
I still don't understand the use case limitation, or exactly where this is a potential issue. Why is the data being interrupted? Is this some kind of raw UDP stream use case?